Wildlife Habitat Effectiveness and Connectivity Project
Oil sands mining activity will result in interim habitat loss, alteration, and fragmentation for resident wildlife during the period between tree clearing and final reclamation (i.e., operational mining). For example, direct habitat loss will stem from the actual development of the mine and its associated infrastructure (e.g., buildings, wastewater ponds, roads, wells, and seismic lines). Indirect habitat loss can also occur if wildlife avoid areas immediately adjacent to the oil sands operations. Avoidance may be related to a variety of factors described above, and the "zone of influence" or "zone of disturbance" extends beyond the physical footprint of individual projects. Habitat loss, alteration, and fragmentation can lead to population declines via:
- Increases in mortality and/or declines in reproductive success if the Athabasca oil sands region no longer provides effective habitat for resident wildlife. There is no "set" definition of habitat effectiveness in the ecological literature, but it generally refers to the ability of the habitat to support wildlife and how this ability is affected by human disturbance (e.g., Suring et al. 1998; Gaines et al. 2005). For example, mining activity may lead to declines in survival and fecundity because of a loss of forage and calving sites (e.g., Rosenberg et al. 1997; Cameron et al. 2005). Habitat alteration could also indirectly lead to reduced survival rates if linear features increase hunter access to wildlife (e.g., Farmer et al. 2006).
- Displacement or emigration to less disturbed areas outside of the oil sands areas and/or reduced immigration into the oil sands area. Also note that while movement to other areas may temporarily "rescue" individuals, the longevity of this effect may depend on the inter- and intraspecific interactions among displaced and resident wildlife. For example, displacement of barren-ground caribou near areas of oil and gas disturbance increases local densities, which may increase competition for food and/or predation risk (Cameron et al. 2005).
- Loss of population connectivity if continuous populations become fragmented and/or if metapopulations are disrupted. Population connectivity reflects the movement of individuals – and thereby flow of genes – between subpopulations (Rosenberg et al. 1997). Movement is often facilitated through the use of natural corridors (e.g., valleys and riparian zones; Rosenberg et al. 1997; Chetkiewicz et al. 2006). Its loss can lead to population isolation and/or small populations. Small populations are more likely to experience the negative effects of low genetic diversity, demographic stochasticity, and environmental stochasticity than larger populations (Caughley and Gunn 1996; Rosenberg et al. 1997). However, the role of river valleys as movement corridors in a boreal landscape are largely unknown as most large mammal corridors have been demonstrated in mountainous terrain (e.g., Chetkiewicz et al. 2006).
If extensive enough, oil sands disturbance may cause "source" habitats within the oil sands area to become "sinks" and/or prevent the "rescuing" of sink habitats via recolonization of the oil sands area (e.g., Pulliam 1988). This could eventually lead to local extirpations and the loss of biodiversity in the oil sands region (e.g., Rosenberg et al. 1997; Chetkiewicz et al. 2006). However, the extent of these effects will likely depend on the overall temporal and spatial scale of the oil sands disturbance. For example, wildlife may move "around" a single mine with little impact on survival, reproductive success, or population connectivity. Population level effects are more likely to occur as development in the area intensifies both temporally and spatially. This implies that the impact of oil sands activity will be cumulative and not immediately evident at the population level (see Schneider 2002). It also implies that as mine activity ceases and sites are reclaimed, the area may be recolonized by wildlife if habitat effectiveness is restored.
It is also possible that some species will be attracted to the oil sands mining activity, which can create human-wildlife conflicts (e.g., black bears may be attracted to human garbage; Breck et al. 2006). Furthermore, industrial activity has been linked to the northward expansion of invasive species like coyotes and deer (Bayne et al. 2004). These species can displace resident prey and thus may alter existing ecological relationships in the Athabasca oil sands region (Bayne et al. 2004). Both human-wildlife conflicts and invasive species are expected to negatively impact resident wildlife.
Our research is aimed at determining three main objectives:
- What is the function of the river and adjacent "set aside" buffers?
- How do mine activities and buffers of different widths affect this function?
- If function is affected by mine activities, are these effects important to regional population dynamics (i.e., effects to dispersers; differences in reproductive output; and population connectivity of the species in question?
WHEC project coordinator: Holger Bohm